Insights Into the Natural History of Recurrent Myocarditis, A Multicenter International Study (Re‐Myo Study)

BACKGROUND: Recurrence of acute myocarditis (AM) is challenging. The management and natural history of patients who experience a recurrence of AM (Re-AM) remain poorly characterized. The aim of this study is to investigate clinical characteristics and outcomes of patients with Re-AM. METHODS: In this international multicenter study, 141 consecutive patients with biopsy-proven or cardiac magnetic resonance-proven Re-AM (35 26-45 years, 77% male, median left ventricular ejection fraction 55%) were investigated and compared with 372 consecutive patients with single acute myocarditis (S-AM). The primary outcome was a composite of all-cause mortality, heart transplant and major ventricular arrhythmias. RESULTS: =0.017). A family history of cardiomyopathy, autoimmune diseases, and ring-like late gadolinium enhancement was independently associated with a higher risk of recurrent AM. CONCLUSIONS: Re-AM is a distinct clinical subgroup of AM associated with generally worse prognosis and a specific increased arrhythmic risk compared with S-AM.